Blind spot detector

ABSTRACT

A warning device for mounting onto a vehicle, in order to attract the attention of the driver when another vehicle ( 2 ) or object is located in a position that is wholly or partially critical for the driver. The device comprises two sources ( 5, 6 ) of laser radiation arranged at a distance from each other, a convex lens ( 8 ) arranged outside of each source and a position-sensitive radiation detector ( 7 ) arranged between the sources ( 5, 6 ). The device reacts with different levels of warning signals on the detection of direction indicator ( 58 ), angular deviation ( 60 ) of a wheel or the steering wheel, speed ( 62 ), etc., in combination.

TECHNICAL FIELD

[0001] The present invention concerns a warning device for mounting ontoa vehicle, in order to attract the driver's attention by means of asignal when an object is located in a position that is wholly orpartially critical for the driver.

BACKGROUND ART

[0002] When, for example, a second vehicle is located in a positiondiagonally behind “one's own” vehicle, normally in a position diagonallybehind one's own vehicle relative to the position of the driving seat,it can be difficult to perceive the second vehicle in the rear-viewmirror, even if this is correctly aligned. It becomes even moredifficult if the mirror is somewhat wrongly aligned. Furthermore, theconstruction of the vehicle normally prevents the peripheral vision ofthe eye from perceiving the second vehicle when the driver looks in therear-view mirror. A further factor that makes it difficult to discoverthe second vehicle in this position is the stress to which the vehicledriver is exposed when driving in heavy traffic, with the requirementfor repeated lane-changes, as is particularly the case in city traffic.

[0003] The Swedish patent application 9700276-0 submitted by the sameapplicant as the present application specifies a warning device formounting onto a vehicle in order to attract the driver's attention bymeans of a signal when an object is located in a position that iscritical for the driver. The device comprises two sources of laserradiation arranged at a distance from each other, a convex lens arrangedoutside of each source, and a position-sensitive radiation detectorarranged between the sources, outside of which is also arranged a convexlens. The sources and the detector are pant of all integrated currentcircuit with the sources modulated to be activated with a phasedisplacement and the beams from the sources are adjusted to intersecteach other at a predetermined distance from the device.

[0004] Other more or less sophisticated devices are available to warmthe driver about other vehicles that are present in the said “blindspot”, that is, diagonally behind one's own vehicle.

[0005] The following documents, U.S. Pat. Nos. 3,732,536; 3,568,144; GB22 65 744 and WO 95/25322, are a selection of those that concern vehicledetection devices for detecting the presence of a vehicle within thesaid “blind spot”, that is, diagonally behind the vehicle that possessesthe said device, by the use of passive ultrasound reception orheat-detection (IR) arrangements. The components that are part of thearrangements are often arranged at different locations on the vehicles.Against the background of the surrounding background radiation noise, itis essentially impossible to make this type of equipment reliable as awarning device of the intended type.

[0006] A device is revealed in DE-2455733 for the measurement of therelative distance to an object that determines the distance to theobject independently of whether the object is close to or far from thedevice.

[0007] Devices equipped with active search means for the discovery of asecond vehicle diagonally behind one's own are also known. These activesearch means thus consist of some type of transmitter of pulses andreceivers for the reception of echoes, which are obtained if the pulsesimpinge upon an object in their pathway. Examples of such devices areshown in DE-21 43 406 and in EP 0 370 965 A2, which devices use Dopplerradar. The complexity of these known devices and the relatively highcosts that are thus associated with them, combined with a large risk forinterruptions in service, have resulted in these known warning devicesnot having found a market. There is a large risk that false echoes arereceived.

[0008] A warning device is known through GB 2283874 that attracts thedriver's attention, for example, through sensing the direction indicatorand the angle of the wheels through sensors for the same.

[0009] The document WO 9013103 displays a warning device for attractingthe attention of the driver of a vehicle in which detectors are arrangedat the rear or side sections of a vehicle, and where the vehicle is alorry.

[0010] A warning device for attracting the attention of the driver of avehicle that takes the speed of the vehicle into consideration is knownthrough the document JP 9132094 through Derwents' abstract 1997-328064.

[0011] However, none of the above-mentioned documents describe a warningdevice in the form of a rear-view mirror for vehicles that emits asignal with the status of a warning with respect to sensors for thedirection indicators, deviation of wheel angle, threshold detection ofthe speed of the vehicle in combination with input signals from othersensors.

[0012] Further, it is desirable that the vehicle does not emit a warningsignal during normal turning in, for example, a roundabout or whenturning comers to the right or left.

SUMMARY OF THE DESCRIBED INVENTION

[0013] The present invention, as it is formulated according to thecharacterising parts of the claims, involves a warning device that drawsthe driver's attention to the critical position of second vehicle orobject relative to the vehicle of the driver, without the positiondetermination being disturbed by background noise or sunlight—backgroundlight-, while at the same time being reliable and easy to keep clean.

[0014] A warning device according to the present invention will withvery great probability save many lives and prevent or guard againsttraffic injuries. The problem of what is known as the “blind spot” isone to which motorists are exposed every day.

[0015] There is currently no warning device in the form of a rear-viewmirror that is sufficiently advanced to take into consideration all ofthe sensor outputs, at one and the same time, that are described in thethree documents GB 2283874, WO 9013103 and JP 9132094, and that inaddition takes into account that an alarm is not to be emitted whenturning a corner.

[0016] Hereby the present invention specifies a warning device in theform of a rear-view mirror for mounting onto a vehicle, in order toattract the driver's attention by means of a signal when an object islocated in a position that is wholly or partially critical for thedriver. The device comprises at least one source of electromagneticradiation or ultrasound together with an arranged position-sensitiveradiation- or sound detector.

[0017] The source and the detector are parts of an electronic circuit,whereby the detector detects the presence of an object in a positionthat is critical for the driver. One output in the circuit for a firstsignal with the status of a warning is activated, whereby a first-levelwarning signal is emitted.

[0018] The electronic circuit for the warning device comprises thefollowing sensor means with associated outputs for the activation ofsignals with the status of a warning:

[0019] sensor means for detection of an input signal on/off from thedirection indicators of the vehicle;

[0020] output in the circuit for activation of a signal with the statusof a warning when the input signal of the direction indicator is on;

[0021] sensor devices that detect an angular deviation of one of thewheels of the vehicle;

[0022] outputs in the circuit for activation of a signal with the statusof a warning when the warning signal is emitted for angular deviation;

[0023] means for determining the speed of the vehicle;

[0024] threshold detection means for speeds, whereby predeterminedthreshold values of speed emit a signal with the status of a warning incombination with input signals from sensor means in the direction ofmotion of the vehicle depending on the detection by the sensor means andthat a maximum angular deviation is specified, which determines that thevehicle is turning a corner, turning left or right, etc.

[0025] In one embodiment of the invention, a further level of signalswith the status of a warning is achieved with the sensor means for thedirection indicator.

[0026] Another embodiment of the invention specifies that a furtherlevel of signals with the status of a warning is achieved with thesensor means for angular deviation.

[0027] Yet another embodiment specifies that a further level of signalswith the status or a warning is achieved with sensor means and detectionof speed depending on the threshold value.

[0028] The detection of speed is deactivated in one embodiment of theinvention when the speed falls below a predetermined minimum speed.

[0029] If the speed of the vehicle is lower than a predetermined maximumspeed, a further level is activated according to one embodiment of theinvention for change of lane or over-taking through detection fromsensor means for the direction indicators and/or angular deviation.

[0030] A further embodiment of the invention specifies that a furtherlevel is activated if the detection of angular deviation is greater thana predetermined angle when the speed is greater than a predeterminedminimum speed.

[0031] If the speed of the vehicle is greater than a predeterminedmaximum speed, a further level is activated when the sensor means fordirection indicators detects that the input signal is on, in oneembodiment of the invention. A further level is activated in oneembodiment when the sensor means detects an angular deviation.

[0032] In one preferred embodiment of the device, it is contained withina rear-view mirror for a vehicle. The rear-view mirror contains abattery for the operation of the device in a further embodiment of theinvention.

[0033] The detector is mounted in one embodiment of the invention on therear section of the vehicle. The detector is mounted in a rear-viewmirror and a further detector is mounted on the rear section of avehicle according to one embodiment in which the detectors collaboratein order to detect reflected signals that are received.

[0034] A further embodiment includes the mounting on the side section ofa vehicle of at least one detector for the detection of reflectedsignals.

[0035] The vehicle in one embodiment with detectors mounted on the side-or rear sections is a lorry or similar vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will hereunder be described in the presentdescription with reference to the attached drawings in order to gain abetter understanding of its embodiments, where:

[0037]FIG. 1 shows schematically two vehicles, whereby the leadingvehicle is equipped with a warning device mounted onto a rear-viewmirror according to the prior art;

[0038]FIG. 2 shows at a larger scale and very schematically the warningdevice according to the prior art;

[0039]FIGS. 3 and 4 show examples of two different possibilitiesaccording to the prior art for fitting the warning device onto an outerrear-view mirror for a vehicle; and

[0040]FIG. 5 shows in a schematic block-diagram form a warning deviceaccording to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0041] FIGS. 1-4 below describe the prior art as it is known from thepublished Swedish patent application with application number 9700276-0,from the same applicant as the present [application].

[0042] In FIG. 1, 1 and 2 denote a first and a second vehicle,respectively, whereby the second vehicle 2 is located diagonally behindto the left of the first vehicle 1. This position of the second vehicle2 is critical for the driver of the first vehicle 1, since he or shewill have great difficulty in discovering the second vehicle 2 in therear-view mirrors of the vehicle, as has been suggested in theintroduction to the description of the patent. The external rear-viewmirrors of the vehicle 1 are denoted by 3. The warning device accordingto the invention is shown in more detail in FIG. 2, which shows veryschematically the principle of the invention. It is to be appreciatedthat the scale and the geometry of FIG. 2 are distorted in comparisonwith FIG. 1, in order to make the principle clearer. Reference symbol 4denotes a cover or housing, in which two sources 5, 6 of electromagneticradiation are arranged at a distance from each other. Aposition-sensitive detector 7, that is, a detector that detects theposition of an incident beam, as will be described later, is arrangedcentrally between the sources 5, 6. The sources of electromagneticradiation 5, 6 and the position-sensitive detector 7 are part of anintegrated current circuit in which the sources are modulated to beactivated with a phase displacement, that is, they are activatedalternately. Laser sources or laser diodes may be used as sources. Suchsources are in themselves well-known, as are position-sensitiveradiation detectors, just as the connections between them that arespecified here constitute an obvious connection circuit for one skilledin the arts. A convex lens 8 may be arranged on the outside of eachsource 5 and 6 and on the outside of the radiation detector 7.

[0043] The source 5 for electromagnetic radiation emits a radiation beamor cone of beams 9, and the source 6 of electromagnetic radiation emitsin the same way a radiation beam or cone of beams 10. In order to makethe picture clear, it must be appreciated that at any moment only one ofthe radiation beams 9 or 10 is activated at any moment in this way. Thefrequency at which the light sources may be modulated to be activatedmay, for example, be 100 Hz. The dashed lines 11 in FIG. 2 specify thecentral axes of the radiation beams 9 and 10. The dotted/dashed line 12shown in FIG. 1 and in FIG. 2 for the purposes of explanation andsimplification denotes the plane of the right-hand side of the vehicle2, which faces the first vehicle 1. This side of the vehicle 2 isassumed in the example to be that side which reflects the radiationbeams 9 and 10, as will be described later. As is probably best madeclear by FIG. 1, the second vehicle 2 will move through or cut theradiation beams 9 and 10, at an angle α in the example shown, whichangle in practice can lie between approximately 15° and 25°.

[0044] When the reflecting part of the vehicle 2 penetrates theradiation beam 9 from the left in FIG. 2, that is, when it is locatedwithin the area marked by B, beams reflected to the position-sensitivedetector 7 will be registered only from the radiation beam 9. Thedetector is modulated such that no signal is emitted in this case. Whenthe reflecting part of the second vehicle 2 penetrates the area in whichthe radiation beams 9 and 10 intersect each other, which area is shownhatched in FIGS. 1 and 2, the reflected beams will be detected in theradiation detector arising from both sources 5 and 6, whereby a signalis emitted, processed and transformed into, for example, a flashinglight that is visible to the driver.

[0045] Assume that if the second vehicle 2 and its reflecting part arelocated at point a in FIG. 2, the reflected beams will take the pathway13 shown dashed and will be detected by the position-sensitive radiationdetector at the point a′. If the second vehicle 2 continues in a forwarddirection relative to the first vehicle 1 and the reflecting part ofthis vehicle 2 reaches point b, the reflected beam 14 will be detectedat the detector 7 at point b′, whereby the detector 7 emits during themotion of the beam from a′ to b′ a signal that is converted to, forexample, a flashing light that is visible to the driver.

[0046] Thus, the reflected beam on the position-sensitive detector 7 hasmoved from point a′ to point b′ during the movement of the secondvehicle 2 from point a to point b. The positions of the reflected beamdetected during the movement of the beam from a′ to b′ are converted tosignals for a board or panel that specifies positions and that isclearly visible to the driver, on which the driver receives informationconcerning the position of the second vehicle relative to his or her ownby means of lamps, symbols or similar. It is, of course, possible forthe positions of the reflected beams between a′ and b′ to be detectedand the subsequent signals processed so that, for example, a lampspecifies only that a vehicle is located in the area of the “blindspot”.

[0047] In that two alternating beams, which are reflected from an objectto the detector, are required in order for the detector to emit thecorrect signals, only the area that is specified by hatching in FIGS. 1and 2 will constitute the “detection area”. The extent of the hatchedarea can be determined by varying the angles of the radiation beams andthe angle of intersection between them, such that the greatest possibleefficiency can be achieved with the device. The design of the deviceensures that all background disturbance, background noise is efficientlyminimised or eliminated, while the effective detection zone of thedevice is limited in space.

[0048] Examples of two different installations on an outer rear-viewmirror for a vehicle are shown in FIGS. 3 and 4. FIG. 3 shows the device4 applied on top of the mirror, and FIG. 4 shows the device 4 appliedvertically along the side of the mirror. The device according to theinvention can be produced as an accessory to existing rear-view mirrors,or it can, of course, be integrated in such mirrors during newproduction. The lamp or lamps that are to attract the driver's attentionto the fact that a vehicle is positioned diagonally behind his or herown vehicle by blinking can be arranged on the rear-view mirror inassociation with the present warning device or it/they may be inside thecar. The first case would be the most appropriate since the driver mustin any case look into the rear-view mirror. It is also possible to useaudible signals.

[0049]FIG. 5 shows schematically in the form of a block diagram awarning device 50 according to the present invention. The device 50comprises an electronic circuit 52 for control of alarm levels; level 1,level 2, level 3, according to the embodiment in FIG. 5. The alarmlevels attract the attention of the driver of a vehicle to criticalconditions, for example, objects such as another vehicle in the blindspot area, by a display 54 with flashing lights of different colours orfrequencies and/or different audible signals.

[0050] The warning device is shown here in the form of several units forobtaining a better overview, but one embodiment of the inventionincludes the containment of the warning device 50 in a rear-view mirror3. The rear-view mirror 3 also includes in one extension of theinvention batteries to drive the device 50 or connections in order toconnect easily the current supply of a vehicle to the mirror 3. Oldervehicles can thus in this way also be supplemented with a warning deviceaccording to the present invention.

[0051] The mirror comprises in one embodiment the devices that have beendescribed above according to the prior art, for example, radiation orsound source, detector, etc. The reference symbol 8 in FIG. 5 shows, ashas been described, lenses for concentrating light from radiationsources that lie behind them, and a lens for a detector of reflectedlight.

[0052] The circuit 52 has a signal bus 56 or similar connected to thedisplay 54 comprising a definite number of outputs for alarm levelsdepending on the number of functions for raising an alarm or warningsignal.

[0053] Different warning signals are given according to the presentinvention depending on the input signals that sensors or sensor meansfor detection of direction indicators 58 on/off, wheel angle 60 (degreeof turning of the steering wheel) and the measured speed 62 of thevehicle supply, as will be described in more detail in the remainder ofthis document.

[0054] Whenever a vehicle equipped with the warning device 50 detects anobject in the blind spot, for example a vehicle, through the detector 7,alarm level 1 will be activated according to the prior art. In order toachieve an even more safe conduct of a vehicle with the device 50, thepresent invention specifies the use of a combination of input signals tothe circuit 52 through sensor means 58, 60, 62. In this way, a level 1alarm is combined with input signals from direction indicators, angle ofdeviation of the wheel or steering wheel and the speed of the vehicleaccording to predetermined parameters such that at least one furtheralarm level, level 2, is activated and, possibly, several furtherlevels, such as alarm level 3. In this way the driver of a vehicle canbe warned more effectively in that further light- and/or audibleindications in a manner of speaking “awaken” the driver, even if he orshe attempts to change lanes or commence an overtaking manoeuvre inspite of alarm level 1.

[0055] In the following, a preferred embodiment follows for the purposesof providing an example, as does one of many other possible suchembodiments.

[0056] As has been described above, alarm level 1 is always given ondetection of an object in a position that is critical or partiallycritical for the driver. In addition to this, warning signals areemitted in the present embodiment for the detection of directionindicator on, alarm level 2, wheel deviation measured in terms of, forexample, angle, level 3 alarm, and consideration of the speed of thevehicle relative to predetermined threshold values depending on thetraffic situation.

[0057] If the vehicle equipped with the warning device 50 travels at aspeed that lies under 60 km/h, an input signal from sensor device 58, 60involves the activation of alarm level 2 and this alarm being madevisible for the driver on the display 54, possibly combined with anaudible alarm. However, alarm level 2 is not emitted if the angle ofdeviation of the wheels is greater than 30°, in this case it is assumedthat the vehicle is turning to the right or left in, for example, a roadjunction. The same occurs if the speed of the vehicle lies under, forexample, 15 km/h since it is not desirable that the alarm is givenduring, for example, crawling during rush-hour driving.

[0058] Numerical examples of speeds and angles of deviation for thewheels are predetermined and can be modified for different trafficsituations.

[0059] If the speed of the vehicle is detected as lying above 60 krn/h,alarm level 2 is activated when the direction indicator is detected asbeing on, and alarm level 3 on deviation of the wheel angle.

[0060] Other conditions for the activation of an alarm than those givenabove are, of course, possible for one skilled in the arts whenconsidering the scope of the attached claims.

[0061] The detector 7 in one embodiment is arranged on the rear sectionof the vehicle. The detector is according to one embodiment arranged ina rear-view mirror and a further detector is arranged on the rearsection of a vehicle, where the detectors collaborate in order to detectreflected signals that are received.

[0062] A further embodiment includes the arrangement of at least onedetector on the side section of a vehicle for detection of reflectedsignals.

[0063] A further embodiment specifies the arrangement of at least onedetector on the side section of a vehicle for the detection of reflectedsignals.

[0064] The vehicle in one embodiment with detectors arranged on theside- or rear sections of the vehicle is a lorry, heavy goods vehicle orsimilar.

[0065] The present invention has been described here using specificembodiments and examples, but is not for that reason limited to these.It is instead the extent of the attached claims that specify furtherembodiments for one skilled in the arts within the present technicalarea.

1. A warning device (50) in the form of a rear-view mirror for mountingonto a vehicle, in order to attract the attention of the driver when anobject is located in a position that is wholly or partially critical forthe driver, whereby the device (50) comprises at least one source (5, 6)of electromagnetic radiation or ultrasound and an arrangedposition-sensitive radiation- or sound detector (7), whereby the source(5, 6) and the detector are part of an electronic circuit (52), wherebythe detector (7) detects the presence of an object in a position that iscritical for the driver, whereby an output (56) from the circuit for afirst signal with the status of a warning is activated, and whereby afirst level (54) warning signal is given, characterized in that theelectronic circuit (52) of the warning device (50) comprises thefollowing sensor means with their associated outputs (56) for activationof a signal with the status of a warning: sensor means for detection ofan input signal on/off (58) from the direction indicators of thevehicle; output (56) in the circuit for activation of a signal with thestatus of a warning when the input signal of the direction indicator ison; sensor means (60) that detect an angular deviation of one of thewheels of the vehicle; output (56) in the circuit for activation of asignal with the status of a warning when the warning signal is emittedfor deviation of the angle; means (62) for determining the speed of thevehicle; threshold detection means for speeds, whereby predeterminedthreshold values of speed emit a signal with the status of a warning incombination with input signals from sensor means (58, 60) in thedirection of motion of the vehicle depending on the detection of atleast one sensor means (58, 60); and threshold detection means for amaximum allowed angular deviation in order for the warning device to beactive, which indicates rounding of a curve or normal turning of thevehicle.
 2. The warning device (50) according to claim 1, characterizedin that a further level of signals with the status of a warning isachieved with the sensor means (58) for the direction indicator.
 3. Thewarning device according to either of claim 1 or claim 2, characterizedin that a further level of signals with the status of a warning isachieved with the sensor means (60) for angular deviation.
 4. Thewarning device according to any one of claims 1-3, characterized in thata further level of signals with the status of a warning is achieved withsensor devices (58, 60) and speed detection depending on the thresholdvalue.
 5. The warning device according to any one of claims 1-4,characterized in that emission of warning signals is deactivated whenthe vehicle travels slower than a predetermined minimum speed.
 6. Thewarning device according to any one of claims 1-5, characterized in thatif the speed of the vehicle lies below a predetermined maximum speed, afurther level is activated for change of lane or overtaking throughdetection from sensor means of direction indicators (58) and/or angulardeviation (60).
 7. The warning device according to claim 6,characterized in that a further level is activated if the detection ofangular deviation lies above a predetermined angle when the speed liesabove a predetermined minimum speed.
 8. The warning device according toany one of claims 1-5, characterized in that if the speed of the vehiclelies above a predetermined maximum speed, a further level is activatedwhen the sensor means (58) for the direction indicator detects that theinput signal is on.
 9. The warning device according to claim 8,characterized in that a further level is activated when the sensor means(60) for angular deviation detects an angular deviation.
 10. The warningdevice according to any one of claims 1-9, characterized in that it iscontained in the rear-view mirror (3) of a vehicle.
 11. The warningdevice according to any one of claims 1-5, characterized in that therear-view mirror contains a battery for operation of the device (50).12. The warning device according to any one of claims 1-11,characterized in that the detector (7) is arranged on the rear sectionof a vehicle.
 13. The warning device according to any one of claims1-11, characterized in that one detector (7) is arranged in a rear-viewmirror (3) and that a further detector (7) is arranged on the rearsection of a vehicle where the detectors collaborate in order to detectreflected signals that are received.
 14. The warning device according toany one of claims 1-13, characterized in that at least one detector (7)is arranged on the side section of a vehicle for detection of reflectedsignals.
 15. The warning device according to any one of claims 13-14,characterized in that the vehicle is a lorry or similar.